In recent years, semiconductor devices have been required to be smaller, thinner, lighter in weight and cheaper in cost in response to the development of information and communication equipment and technical advancements such as a higher speed of signal processing as well as employing a higher frequency. Semiconductor devices as small as a semiconductor IC (bare chip) are proposed in various forms.
FIG. 8 and FIG. 9 illustrate a general construction of a semiconductor device, i.e. electrode pad 103a is disposed on board 101 so that pad 103a faces to electrode 106 of semiconductor IC 105. Further, wiring pattern 102 is provided with pad 103a in order to electrically couple pad 103a to a mother board (not shown). Electrode 106 of semiconductor IC 105 is coupled to electrode pad 103a of board 101 via protrusion 103b such as a semiconductor bump formed on each electrode 106. Protrusions 103b are formed on respective electrodes 106 individually by using bump-forming-apparatus 110 shown in FIG. 10.
In the conventional construction discussed above, protrusions 103b are individually formed on respective electrodes 106. This time consuming process prevents a forming time from being shortened. As a result, this type of construction has been a bottleneck for reducing the cost of semiconductor devices. Further, respective protrusions 103b are desirably formed in an identical shape and at the same height so that electrode 106 of IC 105 can be perfectly conductive with electrode pad 103a of board 101. However, the conventional method discussed above rarely produces protrusions 103b in the identical shape.